C# Membership.ValidateUser返回：null

我使用AspNetSqlMembershipProvider创建登录门户

<membership defaultProvider="AspNetSqlMembershipProvider">
 <providers>
    <remove name="AspNetSqlMembershipProvider"/>
    <add name="AspNetSqlMembershipProvider" requiresQuestionAndAnswer="false" enablePasswordRetrieval="false" enablePasswordReset="true" connectionStringName="MembershipDB" minRequiredPasswordLength="8" minRequiredNonalphanumericCharacters="1" applicationName="php" type="System.Web.Security.SqlMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>

我检查了数据库。用户名和密码都在那里。 谢谢你的帮助

更新：返回false。 然后

MembershipUser=Membership.GetUser（loginInitial.UserName）用户返回
null

再次更新：更多代码，
eror消息是：“无效用户名和/或密码”
您应该做的第一件事是检查数据库中是否存在该用户。
您可能正在使用两个不同的数据库，一个用于本地，另一个用于生产。
能否显示AspNetSqlMembershipProvider的连接字符串

*编辑*
我不是连接字符串方面的专家，但在我看来，您运行的是sql compact db。我将使用vs或sql manager中的服务器资源管理器连接到db，检查aspnet_Users表，并验证您的用户是否存在

您是在本地测试还是在生产机器上测试？如果在生产环境中，它是否在本地工作？
MembershipProvider.ValidateUser返回布尔值。你可能是说它返回了false，而不是null。只能返回true或false。即使您没有显示完整的代码，我假设您仅在ValidateUser返回true时调用Membership.GetUser。所以我不理解您更新的问题，您说ValidateUser返回false，但Membership.GetUser为null（您通常不应该到达这一点）。表“aspnet_成员资格”中有一个字段“IsApproved”。一旦这是真的，那么一切都很好。默认情况下为false。
   protected void Login1_Authenticate(object sender, AuthenticateEventArgs e)
   {
            bool UserAuthenticated = false;
            MembershipProvider AuthenticationProviderUsed = null;
            RoleProvider roleProvider = Roles.Providers["SqlRoleProvider"];
            // Try authenticating the user against each membership provider
            foreach (MembershipProvider membershipProvider in Membership.Providers)
            {
                try
                {
                    if (membershipProvider.ValidateUser(loginInitial.UserName, loginInitial.Password)) // here got null.
                    {

    protected void Login1_Authenticate(object sender, AuthenticateEventArgs e)
    {
            bool UserAuthenticated = false;
            MembershipProvider AuthenticationProviderUsed = null;
            RoleProvider roleProvider = Roles.Providers["SqlRoleProvider"];
            // Try authenticating the user against each membership provider
            foreach (MembershipProvider membershipProvider in Membership.Providers)
            {
                try
                {
                    if (membershipProvider.ValidateUser(loginInitial.UserName, loginInitial.Password))
                    {
                        if (base.ConfigSettings.OperatingMode == ConfigurationSettingValues.OperatingModes.NoAccess)
                        {
                            if (!roleProvider.IsUserInRole(loginInitial.UserName, ConfigurationManager.AppSettings["AdminRole"]))
                            {
                                FormsAuthentication.SignOut();
                                return;
                            }
                        }

                        MembershipUser usrInfo = Membership.GetUser(loginInitial.UserName);
                        if (membershipProvider.Name == "ActiveDirectoryMembershipProvider")
                        {
                            System.Web.Security.FormsAuthentication.SetAuthCookie(loginInitial.UserName, loginInitial.RememberMeSet);
                            UserAuthenticated = true;
                            AuthenticationProviderUsed = membershipProvider;
                            break;
                       }
                        else
                        {
                            
                            Int16 daysSincePwdChange = Convert.ToInt16(DateTime.Now.Subtract(usrInfo.LastPasswordChangedDate).TotalDays);

                            System.Web.Security.FormsAuthentication.SetAuthCookie(loginInitial.UserName, loginInitial.RememberMeSet);

                            if (daysSincePwdChange > SecurityUtils.DefaultPasswordExpiryInDays || usrInfo.Comment == "ChangePassword")
                            {
                                 e.Authenticated = false;
                                Response.Redirect("~/admin/ChangePassword.aspx?UserName=" + Server.UrlEncode(loginInitial.UserName));
                             }
                            else
                            {

                                System.Web.Security.FormsAuthentication.SetAuthCookie(loginInitial.UserName, loginInitial.RememberMeSet);
                                UserAuthenticated = true;
                                AuthenticationProviderUsed = membershipProvider;
                                break;
                            }
                        }
              
                   }
                    else
                    {
                        // See if the user is locked out
                        MembershipUser user = Membership.GetUser(loginInitial.UserName);
                        if (user != null && user.IsLockedOut)
                        {
                            ErrorMessage.Text = "Your account is currently locked out.  Please contact the system administrator.";
                        }
                        else
                        {
                            ErrorMessage.Text = "Invalid user name and/or password";
                            //Response.Write("Invalid User Name or Password");
                        }
                    }
                }

                catch (Exception ex)
                {
                       LoggingLibrary.LogException(this.Logger, Context, ex, ex);

                }
            }